Physical activity and sitting time in adults after positive diagnosis for COVID-19: a cross-sectional study / Atividade física e tempo sentado em adultos após diagnóstico positivo para COVID-19: um estudo transversal

This study aimed to: a) investigate the most common signs and symptoms reported by people infect-ed by the COVID-19, b) compare total time and weekly level of physical activity of people between pre- and post-infection period, and c) examine the association between physical activity levels and signs and symptoms reported during the disease cycle. Twenty-two adult people (14 males and 8 females, mean age 37.9 ± 16.8 years) living in Ribeirão Preto, Brazil participated in this study. Par-ticipants received a positive diagnosis for COVID-19 by PCR. Physical activity and sitting time was assessed using the International Physical Activity Questionnaire. Variables such as body mass index and the clinical condition of the disease (signs and symptoms) were collected. The most frequent signs and symptoms reported by active and inactive individuals, respectively, were loss of taste (77.8% and 25%), headache (66.7% and 25%), coughing (66.7% and 25%), difficulty breathing (61.1% and 25%), and sore throat (61.1% and 75%). A 120-minute reduction (p = 0.010) in the total time of weekly physical activity and a 155-minute reduction (p = 0.003) of weekly moderate physical activity was observed in the pre- and post-diagnostic COVID-19 infection comparison. There was further an association between difficulty breathing and being physically inactive (odds ratio = 0.222; 95%CI: 0.094 ­ 0.527). Our findings suggest that COVID-19 had a negative impact on physical activity and that being physically active may reduce the likelihood of presenting with difficulty breathing if infected with the SARS-CoV-2 and associated disease COVID-19

Este estudo teve como objetivo: a) investigar os sinais e sintomas mais comuns relatados por pessoas infectadas por COVID-19, b) comparar o tempo total e o nível semanal de atividade física das pessoas no período pré e pós-infecção, c) examinar a associação entre os níveis de atividade física e os sinais e sintomas relatados du-rante o ciclo da doença. Participaram deste estudo 22 pessoas (14 do sexo masculino e oito do feminino, idade média 37,9 ± 16,8 anos) residentes na cidade de Ribeirão Preto, Brasil. Todos receberam diagnóstico positivo para COVID-19 via PCR. A atividade física e o tempo sentado foram avaliados por meio do Questionário Internacional de Atividade Física. Variáveis como índice de massa corporal e o quadro clínico da doença (sinais e sintomas), foram coletadas. Os sinais e sintomas mais frequentes foram perda do paladar (77,8% e 25%), dor de cabeça (66,7% e 25%), tosse (66,7% e 25%), dificuldade para respirar (61,1% e 25%) e dor gar-ganta (61,1% e 75%), para indivíduos ativos e inativos, respectivamente. Uma redução de 120 minutos (p = 0,010) no tempo total de atividade física semanal e de 155 minutos (p = 0,003) de atividade física moderada semanal foi observada na comparação pré e pós-diagnóstico por COVID-19. Houve associação entre dificul-dade para respirar e ser fisicamente inativo (odds ratio = 0,222; IC95%: 0,094 ­ 0,527). Nossos resultados sugerem que a COVID-19 teve impacto negativo na atividade física e que pessoas fisicamente ativas podem reduzir a probabilidade de apresentar dificuldade para respirar quando diagnosticadas por COVID-19

Classification of nutritional status by fat mass index: does the measurement tool matter? / Classificação do estado nutricional pelo índice de massa gorda: o instrumento de medição importa?

Abstract Assessment of the Nutritional Status (NS) allows screening for malnutrition and obesity, conditions associated with chronic non-communicable diseases. The fat mass index (FMI) stands out concerning traditional NS indicators. However, proposals that define thresholds for FMI are not sensitive to discriminate extreme cases (degrees of obesity or thinness). Only one proposal (NHANES), determined by total body densitometry (DXA), established eight categories of NS classification (FMI). However, DXA is expensive and not always clinically available. Our study aims to test the validity of the NHANES method using electrical bioimpedance (BIA) and skinfold thickness (ST) to classify NS. The FMI of 135 (69 women) university students aged 18 to 30 years old was determined using DXA, BIA, and ST. The agreement between the instruments (Bland-Altman) and the agreement coefficient in the NS classifications (Chi-square and Kappa index) were tested. The agreement test against DXA indicated that ST underestimated the FMI (-1.9 kg/m2) for both sexes and BIA in women (-2.0 kg/m2). However, BIA overestimated FMI (1.4 kg/m2) in men, although with less bias. There was no agreement between the NS classifications (NHANES) by FMI between DXA and BIA, or DXA and ST. The exception occurred between DXA and BIA in men who showed a slightly better consensus, considered "fair" (k = 0.214; p = 0.001). In conclusion, ST and BIA did not show enough agreement to replace DXA for NS classification, within NHANES thresholds. The FMI measurement tools for the NHANES classification of the categories of NS matters.

Resumo Avaliar o Estado Nutricional (EN) permite rastrear desnutrição e obesidade, condições associadas a doenças crônicas não transmissíveis. O índice de massa gorda (IMG) destaca-se em relação aos indicadores tradicionais de EN. No entanto, propostas que definem limiares para IMG não são sensíveis para discriminar casos extremos (graus de obesidade ou magreza). Apenas uma proposta (NHANES) estabeleceu oito categorias de classificação EN (IMG), mas foi determinada por densitometria corporal total (DXA). Porém, DXA é caro e nem sempre disponível. O objetivo foi testar a validade do método NHANES usando bioimpedância elétrica (BIA) e dobras cutâneas (DOCs) para classificar o EN. O IMG de 135 (69 mulheres) universitários com idade entre 18 e 30 anos foi obtido por DXA, BIA e DOCs. A concordância foi testada entre os instrumentos (Bland-Altman) e classificações de EN (Qui quadrado e índice Kappa). O teste de concordância com a DXA indicou as DOCs subestimarem o IMG (-1,9 kg/m2) para ambos os sexos e a BIA em mulheres (-2,0 kg/m2). No entanto, as BIA superestimaram o IMG (1,4 kg/m2) nos homens, embora com menos viés. Não houve concordância entre as classificações de EN (NHANES) pelo IMG entre DXA e BIA/DOCs. A exceção ocorreu entre DXA e BIA em homens que apresentaram concordância "razoável" (k = 0,214; p = 0,001). Em conclusão, DOCs e BIA não mostraram concordância suficiente para substituir DXA pela classificação de EN, dentro dos limites NHANES. As ferramentas diferem para medir IMG e classificar categorias de EN (NHANES).

Validation of anthropometric models in the estimation of appendicular lean soft tissue in young athletes / Validação de modelos antropométricos na estimação da massa isenta de gordura e osso apendicular em jovens atletas

Abstract Magnetic resonance imaging and Computer tomography are gold standards in the measurement of muscle tissue (MT), but are expensive. Dual Energy X-Ray Absorptiometry (DXA) is also costly but safer and allows for the measurement of Appendicular Lean Soft Tissue (ALST), a strong predictor of MT. Alternatively, there are anthropometric models that predict the ALST of Portuguese athletes with low cost/risk that have not been validated in other populations. The aim of this study was to validate anthropometric Portuguese models that predict ALST in young athletes or, if the validation fails, to propose new models. The ALSTDXA of 174 young athletes was determined by DXA. Two anthropometric models (ALSTmod1 and ALSTmod2) measuring ALST among Portuguese athletes were tested. To validate the coefficient of determination, the difference (bias) and concordance correlation coefficient between predicted and actual values were computed. Finally, association between mean and difference of methods was verified. Validation failed and, for this reason, new multiple regression models were proposed and validated using PRESS statistics. The Portuguese models explained ~96% of the ALSTDXA variability. The difference between ALST (-0.7kg) was less than that found for the ALSTmod2 and ALSTDXA limits of agreement from 3.6 to -2.1 and from 6.1 to -1.5kg, respectively. The new models included three predictive equations for ALST. Only ASLTmod1was valid; however, it was prone to bias, depending on the magnitude of ALST values. The newly proposed models present validity with greater concordance (r2PRESS=0.98), lower standard error of estimate (SEEPRESS [kg]=0.91) and more homogeneous predicted extreme values.

Resumo Ressonância magnética e tomografia computadorizada são referências para medir o tecido muscular (TM), porém apresentam custo elevado. A Absorciometria Radiológica de Dupla Energia (DXA) é segura, embora ainda dispendiosa, permite medir a Massa Isenta de Gordura e Osso apendicular (MIGOap), forte preditor do TM. Alternativamente, existem modelos antropométricos preditivos da MIGOap de atletas portugueses com baixo custo/risco, porém sem validação para outras populações. Objetivou-se validar modelos antropométricos portugueses preditivos da MIGOap em jovens atletas ou propor novos modelos, caso a validação falhe. A determinação da MIGOapDXA de 174 jovens atletas foi realizada por DXA. Dois modelos antropométricos (MIGOapmdJ1 e MIGOapmd2) de atletas portugueses foram testados para predizer MIGOap. Para validação o coeficiente de determinação, a diferença (viés) e a concordância entre valores medidos e preditos foram calculados. Finalmente, a associação entre média-e-diferença dos métodos foi calculada. A validação falhou, assim foram propostos novos modelos de regressão múltipla validados por estatística PRESS. Os modelos portugueses explicaram ~96% da variabilidade da MIGOapDJAf A diferença entre MIGOapmod1 e MIGOapDXA (-0,7kg) foi menor do que MI-GOapmod2 (-2,3kg), com limites de concordância de3,6 a -2,1 e de 6,1 a -1,5kg, respectivamente. Os novos modelos incluíram três equaçõespreditivaspara MIGOap. Somente MIGOapmd1foi válido, todavia mostrou grande tendência a vieses, conforme magnitude dos valores de MIGOap. Os novos modelos propostos mostraram validade com maior concordância (r2PRESS=0,98), menores erros de estimativa (EPEPRESS =0,91) e valores preditos mais homogêneos para casos extremos.

Estimate of Resting Energy Expenditure by DXA in Boys of Different Nutritional Statuses

Abstract Aim: to estimate the resting energy expenditure (REE) of organ tissue components using Dual Energy x-ray Absorptiometry (DXA) in pubertal boys. The mass of components and REE were compared among groups of different nutritional statuses. Methods: a sample of 278 boys (13.7 ± 2.4 years old) was grouped according to BMI nutritional status for Brazilian children and adolescents1 such as Underweight (UW), Normal weight (NW), Overweight (OW), and Obese (OB). The REE of organ tissue components given by DXA was calculated using specific models for skeletal muscle tissue (SMT), adipose tissue (AT), bone tissue (BT) and residual tissue (RT) based on previous reports. The absolute and relative REE (REEDXA) of each component were statistically compared among groups. Results: No differences of total REEDXA were found among nutritional groups (F(3, 274)=0.071, p=0.976). When, however, specific REE was considered per component, differences were found for BT and REEBT between NW-OW (p=0.003) and NW-OB (p=0.048); in AT and REEAT for all the groups (p<0.001), except between UW-NW (p=1.000); in RT and REERT between NW-OB (p=0,022) and SMT and REESMT (p=0,039). Greater proportions of organ tissue of RT and high metabolic rates, were observed in the UW group (78.3%) in comparison to the OB group (60.7%). Conclusion: This approach provides a new opportunity to examine energy metabolism for individual differences of pediatric populations. It is an applicable strategy both to prescribe exercises and to administer diets to this population, as it reveals the magnitude of heat-producing body components.